P174 Scientific Sessions--Wednesday Otolaryngology- Head and Neck Surgery August 1999 cases are presented, each of which required extensive recon- struction following traumatic or surgically created defects in the facial skeleton. The defects reconstructed were the result of orbital and mandibular trauma or oncologic resections. Methods: SL allows the accurate reproduction of both internal and external anatomy of body structures. The individ- uals were scanned using 3-dimensional CT preoperatively, and data from these scans was used to create SL models of the patients' defect. In some cases it was used for evaluating the physical dimensions and 3-dimensional relationship for surgi- cal planning. In other cases it was used to actually prefabricate a custom-fit prosthesis or reconstruction plating for intraoper- ative implantation. Results: In the cases where the model was used for simple evaluation, it is difficult to actually quantify the benefits. Subjectively, in the surgeons' experience, the models enhanced the preoperative planning in better estimating both the extent of a procedure and the required support (operating room time, equipment, plating sets, hydroxy appetite cement, etc). In the cases where the model was used for prefabrication of implants or plating, this method unquestionably decreased the intraop- erative time, by several hours in some cases, while providing more accurate reconstruction prosthesis. Conclusions: The SL model provides highly accurate 3- dimensional models that can be utilized for preoperative eval- uation and planning as well as prefabrication of the prosthesis and plating while decreasing operative times and enhancing results. 8:08 AM Optical Coherence Tomography and Fluorescence Spec- troscopy of Transformed Oral Tissue MASSOUD M 9 PHD (presenter); MOUWAFAK MUFLIH AL-RAWI MD; EW J VAN DER BREGGEN MS; KAREN H CALHOUN MD; H K M STERENBORG PHD; ASHLEYJ WELCH; Galveston TX; Galveston TX; Haarlem Netherland; Galveston TX; Capelle D Ijssel Netherlands; Austin TX Objectives: To investigate the biochemical and morpho- logical changes in oral tissue during benign and malignant transformation in 2 hamster models by employing a combina- tion of fluorescence spectroscopy and optical coherence tomography (OCT), a new optical imaging technique with near-microscopic spatial resolution. Methods: The fiberoptic autofuorescence and bench-optic OCT measurements were done almost simultaneously. Quanti- fication methods involved ratio analysis to quantify fluores- cence spectral (red/orange) and measurements of the thick- ness of mucosa in the OCT images to quantify changes in the tissue architecture. Results: OCT provides details visible up to 2 mm mucosal thickness. Mucosal thickness ranged from 75 _+ 9 ~tm in nor- mal tissue to 130 _+ 30 l.tm in both benign and premalignant lesions and could differentiate between treated and untreated mucosa (P < 0.05). The red/orange ratio showed an increase in normal (0.49 _+0.07) versus premalignant tissue (1.3 _+ 0.8) and was unchanged in the benign lesions (0.492 _+ 0.007). The blue tumor-to-normal ratio was decreased in premalignant tis- sue (0.5 -+ 0.3) compared with normal tissue (0.9 -+ 0.3), whereas it was similar to normal in the benign lesions (1.1 _+ 0.2). During development from normal to premalignant there was an increase in both the thickness of mucosa and the red- orange ratio, with the correlation factor between these two being 0.8. No such correlation in increase was noted in the benign lesions. Conclusion: This study suggests that in the early stage of mucosal epithelial lesion development, a combination of OCT and autofluorescence could provide a high tumor sensitivity. The loss of stratified architecture in the OCT images suggests a role for this technique in tumor detection. The application of fuorescence detection, on the other hand, is more practical in the fast scanning of large surface areas of mucosa and pro- vides information on biochemical changes in tissue. 8:16 AM Ultrasound Guided Fine Needle Aspiration and Thyroid Disease KENNETH A NEWKIRK MD (presenter); KENNETH D BURMAN MD; MATTHEW D RINGEL MD; JAMES JELINEK MD; ZIAD E DEEB MD; ALEXANDER S MARK MD; Fairfax VA; Washington DC; Washington DC; Washington DC; Washington DC; Washington DC Objectives: Fine-needle aspiration (FNA) is a valuable part of the diagnosis and management of thyroid disease. The unity of ultrasound-guided FNA (USFNA) as an effective diagnostic tool has increased over the past 2 decades. However, as an evolving technology, standardization of indi- cations for its use has not been fully addressed. This study attempts to address the issues of accuracy of USFNA and to determine indications for its use. Methods: A retrospective chart review was performed in 166 patients (139 women and 27 men) undergoing USFNA at a tertiary care medical center. Sensitivity, specificity, accura- cy, positive predictive (PPV), and negative predictive (NPV) values; the inadequacy rate; the complication rate; and the cancer yield were assessed. Results: The mean ages for women and men were 52.1 (SD _+ 14.8) and 58.4 (SD -+ 15.4) years. Comparing final cytopathologic diagnosis to the preliminary reading at the time of the biopsy, the sensitivity was 88%, the specificity was 98%, and the PPV, NPV, and accuracy were 82%, 98%, and 96%, respectively. Comparing cytopathology to histologic diagnosis (N = 25), sensitivity was 86%, specificity was 89%, the PPV was 75%, the NPV was 94%, and the accuracy was 88%. The mean nodule size was 2.2 cm (SD _+ 1.1, range 0.5- 6.2 cm), with an average of 4.7 passes (SD + 2.1) per biopsy. The cancer yield was 24% (6/25), and the inadequacy rate was